In the semiconductor industry, the basic steps of the conventional method of manufacturing P-doped gate structures have been fairly standardized. The process begins with the silicon substrate upon which a layer of barrier oxidation is positioned. After various steps, areas of field oxide become situated between blocks of barrier nitride. Gate oxide is then typically grown between the areas of field oxide. A layer of polysilicon is typically positioned over the areas of field oxide and the gate oxide. Then, through various steps, a block of polysilicon is situated above the gate oxide. Finally, boron diflouride (BF.sub.2) is implanted in the polysilicon. Subsequent to the BF.sub.2 implantation, rapid thermal anneal (RTA) is typically initiated wherein the wafers are heated and the implants are activated and driven.
During the implantation step, boron has a strong tendency to diffuse through the oxide and into the substrate. This diffusion of boron causes the reliability of the semiconductor device to be compromised. In the current conventional processing methods, there is nothing to impede the progress of boron diffusion. Thus, there is a need for an improved semiconductor device and an improved processing method which impedes the diffusion of boron through the gate oxide. The present invention addresses such a need.